gms | German Medical Science

55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

25. bis 28.04.2004, Köln

Differentiation of 74 intracerebral lesions with 18F-Fluorethyl-Tyrosin-PET

Untersuchung von 74 intrazerebralen Läsionen mit 18F-Fluorethyl-Tyrosin-PET

Meeting Abstract

  • corresponding author Frank Willi Floeth - Neurochirurgische Klinik, Heinrich-Heine-Universität, Düsseldorf
  • D. Pauleit - Nuklearmedizinische Klinik, Heinrich-Heine-Universität, Düsseldorf
  • G. Reifenberger - Institut für Neuropathologie, Heinrich-Heine-Universität, Düsseldorf
  • H. J. Steiger - Neurochirurgische Klinik, Heinrich-Heine-Universität, Düsseldorf
  • M. Sabel - Neurochirurgische Klinik, Heinrich-Heine-Universität, Düsseldorf

Deutsche Gesellschaft für Neurochirurgie. Ungarische Gesellschaft für Neurochirurgie. 55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie. Köln, 25.-28.04.2004. Düsseldorf, Köln: German Medical Science; 2004. DocMO.09.09

The electronic version of this article is the complete one and can be found online at:

Published: April 23, 2004

© 2004 Floeth et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




In newly diagnosed intracerebral lesions serial biopsy is necessary to differentiate tumorous from non-tumorous lesions. The aim of this prospective study was to obtain the predictive value of metabolic imaging with PET using the amino acid 18F-Fluorethyl-L-Tyrosin (FET) in lesions being suspected as glial tumours.


Seventy-two Patients with 74 distinct lesions suspected to be gliomas underwent evaluation with contrast-enhanced MRI and FET-PET. A positive result indicating tumour tissue was assumed if PET showed an increased amino acid uptake with a minimum tumour/brain ratio of 1.6 and a diameter of at least 1 cm. All lesions underwent a subsequent neuronavigated serial biopsy in different areas with special attention to PET-positive areas. Biopsy locations were labelled with titanium pellets.


Biopsies from 99 different areas within the 74 lesions were obtained. In 60 areas both MRI and FET-PET indicated tumour tissue and the biopsies confirmed glioma in 56 areas (93 % positive predictive value). In 39 areas only MRI showed tumour features, but FET-PET was negative with no increased uptake. Only in 10 of these areas biopsy revealed glioma tissue (26 % positive predictive value). Regarding the 74 lesions as a whole, 58 lesions were FET-PET positive and biopsy confirmed the diagnosis of glioma in 56 cases (97 % specificity). In 2 lesions FET-PET was false positive. 16 lesions were FET-PET negative and in 10 cases no tumour tissue was found in the biopsies (63 % sensitivity). In 6 of these lesions glioma tissue was found, thus FET-PET was false negative. In 6 of 62 biopsy proven gliomas (10 %) there was no apparent uptake of the amino acid FET.


FET-PET investigation is very specific (3 % false positive results) but not very sensitive (37 % false negative results) in the prediction of the result of biopsy in newly diagnosed lesions suspected to be gliomas. In case of a positive FET-PET, biopsy should be taken from the PET-positive areas, since this strategy will lead to tumour diagnosis in nearly all cases (93 %).